Numeration as on image of next growth stage at Cornu aspersum juvenile. Diameter 12mm. Stockport, England. May 2018. . 3 & 5 not applicable to this image.
1: Large protoconch lacking pattern or sculpture, formed while embryo within egg capsule.
A large, relative to shell size, protoconch is indicative of juvenile stages. Small species with adult shells of this size have proportionally smaller protoconchs.
2: Earliest post-emergence shell. Pattern of spiral lines that might be mistaken for other species, such as Cepaea; differs from adult pattern of variable broad bands and blotches, see flic.kr/p/JSy . N.B. juveniles often have translucent shells that show the pattern of the viscera within which may be mistaken for shell-patternation. The animal has been removed from the shell illustrated above.
3: N/A
4: Growth line separating growth stage ‘1’ from ‘2’.
5: N/A
6: Thin fragile lip, broken in parts, differs from strong lip of adults.
7: Open circular umbilicus. Adult C. aspersum, as described in identification aids, lack an open umbilicus or marked depression.